Effects of Rainfall on the Characteristics of Soil Greenhouse Gas Emissions in the Wetland of Qinghai Lake

Niaodao, a lakeside wetland, was used as the focus of this study to investigate the effect of rainfall changes on the greenhouse gas fluxes of wetland ecosystems. Wetland plots with different moisture characteristics (+25%, −25%, +75%, and −75% rainfall treatments and the control treatment (CK)) were constructed to observe in situ field greenhouse gas emissions at 11:00 and 15:00 (when the daily mean values were similar) in the growing season from May to August 2020 by static chamber–gas chromatography and to investigate the responses of wetland greenhouse gases to different rainfall treatments. The results showed the following: (1) The carbon dioxide (CO2) flux ranged from −49.409 to 374.548 mg·m−2·h−1. The mean CO2 emission flux was greater at 11:00 than at 15:00, and the +25% and +75% treatments exhibited substantially higher CO2 emissions. In addition, the CO2 flux showed a small peak at the beginning of the growing season when the temperature first started to rise. All treatments showed the effect of the CO2 source, and their effects were significantly different. (2) The methane (CH4) flux ranged from −213.839 to 330.976 µg·m−2·h−1 and exhibited an absorption state at 11:00 and an emission state at 15:00. The CH4 emission flux in August (the peak growing season) differed greatly between treatments and was significantly negatively correlated with the rainfall amount (p < 0.05). (3) The nitrous oxide (N2O) flux ranged from −10.457 to 16.878 µg·m−2·h−1 and exhibited a weak source effect throughout the growing season, but it was not significantly correlated with soil moisture; it was, however, negatively correlated with soil temperature. (4) The different treatments resulted in significant differences in soil physical and chemical properties (electrical conductivity, pH, total soil carbon, and total soil nitrogen). The rainfall enhancement treatments significantly improved soil physical and chemical properties.

Effects of Drainage on Greenhouse Gas Emissions and Yields of Lowland Rice-Wheat Rotation System in East China

The subtropical region of East China is characterized by abundant water and temperature resources conducive to crop cultivation, and large areas of lowland have been widely used for agricultural planting. To explore the feasible methods of greenhouse gases (GHGs) reduction for rice-wheat rotation system, shallow ditch (SD) and deep ditch (DD) treatments in the wheat season were set up for drainage to control the water content in soil, with the conventional non-ditching treatment as the control group (CG). Results showed that methane (CH4) emissions from paddy soil were in the majority in global warming potential (GWP) in rice-wheat rotation system. In the three years, compared with that of CG, the CH4 cumulative emissions of SD and DD were reduced by 65.80% and 63.42% (rice season), and 101.37% and 77.28% (wheat season), respectively; the nitrous oxide (N2O) cumulative emissions of SD and DD were reduced by 27.62% and 11.30% (rice season), and 1.53% and -37.40% (wheat season), respectively; the total GWP produced by SD and DD in the three years was reduced by 58.78% and 52.22%, respectively; GHG emission intensity (GHGI) of SD and DD declined by 60.67% and 53.85%, respectively; the CH4 emission flux was significantly positively correlated with atmospheric temperature and 5 cm ground temperature, but negatively correlated with soil Eh; when the soil Eh value was lower than -150 mV, the CH4 emission flux increased significantly, indicating that -150 mV was the key soil Eh value for CH4 emissions in this area; in addition, both SD and DD led to markedly decrease in soil organic matter content and an increase in soil pH. The findings indicate that SD and DD not only ensure stably increasing production, but also effectively reduce GHG emissions.

Greenhouse gas emission fluxes from peat bogs in the Arak Lake Basin in 2021

Climate change has an important impact on greenhouse gas emissions from wetland ecosystems. The static box-meteorological chromatography method was used to determine the CO2 and CH4 emission fluxes of hummocky and hollow in the peat bogs in the Arak Lake Basin during the growing season in 2021. The results showed that the peaks of the CO2 and CH4 emission fluxes in the growing seasons of the hummocky and hollow appeared in July, and their value in May is the lowest. The average C02 emission flux (376.39±56.14 mg-m-2-h-1) during the growing season of hummocky is higher than that of hollow (167.36 mg-m-2-h-1), while the average emission flux of CH4 during the growing season of hummocky (2.00±0.31 mg-m-2-h-1) is lower than that of hollow (3.04 mg-m-2-h-1). The climatic fluctuations have caused differences in the CO2 and CH4 emission fluxes of the same micro-topography in the study area during the growing season between 2020 and 2021.

A Morphological Classification of 18,190 Molecular Clouds Identified in 12CO Data from the MWISP Survey

We attempt to visually classify the morphologies of 18,190 molecular clouds, which are identified in the 12CO(1–0) spectral line data over ∼450 deg2 of the second Galactic quadrant from the Milky Way Imaging Scroll Painting project. Using the velocity-integrated intensity maps of the 12CO(1–0) emission, molecular clouds are first divided into unresolved and resolved ones. The resolved clouds are further classified as nonfilaments or filaments. Among the 18,190 molecular clouds, ∼25% are unresolved, ∼64% are nonfilaments, and ∼11% are filaments. In the terms of the integrated flux of 12CO(1–0) spectra of all 18,190 molecular clouds, ∼90% are from filaments, ∼9% are from nonfilaments, and the remaining ∼1% are from unresolved sources. Although nonfilaments are dominant in the number of the discrete molecular clouds, filaments are the main contributor of 12CO emission flux. We also present the number distributions of the physical parameters of the molecular clouds in our catalog, including their angular sizes, velocity spans, peak intensities of 12CO(1–0) emission, and 12CO(1–0) total fluxes. We find that there is a systematic difference between the angular sizes of the nonfilaments and filaments, with the filaments tending to have larger angular scales. The H2 column densities of them are not significantly different. We also discuss the observational effects, such as those induced by the finite spatial resolution, beam dilution, and line-of-sight projection, on the morphological classification of molecular clouds in our sample.

Photometric Observations of Aerosol Optical Properties and Emission Flux Rates of Stromboli Volcano Plume during the PEACETIME Campaign

The characterisation of aerosol emissions from volcanoes is a crucial step towards the assessment of their importance for regional air quality and regional-to-global climate. In this paper we present, for the first time, the characterisation of aerosol emissions of the Stromboli volcano, in terms of their optical properties and emission flux rates, carried out during the PEACETIME oceanographic campaign. Using sun-photometric observations realised during a near-ideal full plume crossing, a plume-isolated aerosol optical depth of 0.07–0.08 in the shorter-wavelength visible range, decreasing to about 0.02 in the near infrared range, was found. An Ångström exponent of 1.40 ± 0.40 was also derived. This value may suggest the dominant presence of sulphate aerosols with a minor presence of ash. During the crossing, two separate plume sections were identified, one possibly slightly affected by ash coming from a mild explosion, and the other more likely composed of pure sulphate aerosols. Exploiting the full crossing scan of the plume, an aerosol emission flux rate of 9–13 kg/s was estimated. This value was 50% larger than for typical passively degassing volcanoes, thus pointing to the importance of mild explosions for aerosol emissions in the atmosphere.

The Effects of Returning Straw and Milk Vetch on Rice Growth and Greenhouse Gas Emissions

The effects of different nitrogen application levels on rice yield and greenhouse gas (NO2, CH4) emissions from rice fields under the combined action of straw and milk vetch. Two treatments were set up in the main area of this experiment: R0 (no straw returned to the field, 0); R1 (amount of straw returned to the field under normal conditions, 6000kg·hm-2). Before turning the straw back into the field, use a circular knife to cut the straw into 10~13cm.And 3 kinds of nitrogen application treatments in the sub-district: N1 (no nitrogen application, 0), N2 (nitrogen application, 15 kg·hm-2), N3 (nitrogen application, 30kg·hm-2), two-factor cross-combination,and a non-nitrogen control CK, total of 7 treatments. The results showed that in 2017, early rice R1N2 treatment increased the most obvious yield, which was 32.44% higher than CK, and late rice R1N1 treatment increased the most significantly, which was 17.91% higher than CK. CH4 emissions is positively correlated with the amount of straw returned to the field, while the amount of N2O is the opposite.The N2O emission flux was highest in the treatment of R1N3, and the CH4 emission flux was the highest in the treatment of R1N2.

India-Asia collision as a driver of atmospheric CO2 in the Cenozoic

Deep Earth degassing is a critical forcing factor for atmospheric CO2 variations and palaeoclimate changes in Earth’s history. For the Cenozoic, the key driving mechanism of atmospheric CO2 variations remains controversial. Here we analyse three stages of collision-related magmatism in Tibet, which correspond temporally with the three major stages of atmospheric CO2 variations in the Cenozoic and explore the possibility of a causal link between these phenomena. To this end we present geochemical data for the three stages of magmatic rocks in Tibet, which we use to inform a model calculating the continental collision-induced CO2 emission flux associated with the evolving Neo-Tethyan to continental subduction over the Cenozoic. The correlation between our modelled CO2 emission rates and the global atmospheric CO2 curve is consistent with the hypothesis that the India-Asia collision was the primary driver of changes in atmospheric CO2 over the Cenozoic.

SO₂ and BrO emissions of Masaya volcano from 2014 to 2020

Masaya (Nicaragua, 12.0∘ N, 86.2∘ W; 635 m a.s.l.) is one of the few volcanoes hosting a lava lake, today. This study has two foci: (1) discussing the state of the art of long-term SO2 emission flux monitoring with the example of Masaya and (2) the provision and discussion of a continuous data set on volcanic gas data with a large temporal coverage, which is a major extension of the empirical database for studies in volcanology as well as atmospheric bromine chemistry. We present time series of SO2 emission fluxes and BrO/SO2 molar ratios in the gas plume of Masaya from March 2014 to March 2020 – covering the three time periods (1) before the lava lake appearance, (2) a period of high lava lake activity (November 2015 to May 2018), and (3) after the period of high lava lake activity. For these three time periods, we report average SO2 emission fluxes of (1000±200), (1000±300), and (700±200) t d−1 and average BrO/SO2 molar ratios of (2.9±1.5)×10-5, (4.8±1.9)×10-5, and (5.5±2.6)×10-5. Our SO2 emission flux retrieval is based on a comprehensive investigation of various aspects of spectroscopic retrievals, the wind conditions, and the plume height. We observed a correlation between the SO2 emission fluxes and the wind speed in the raw data. We present a partial correction of this artefact by applying dynamic estimates for the plume height as a function of the wind speed. Our retrieved SO2 emission fluxes are on average a factor of 1.4 larger than former estimates based on the same data. Further, we observed different patterns in the BrO/SO2 time series: (1) an annual cyclicity with amplitudes between 1.4 and 2.5×10-5 and a weak semi-annual modulation, (2) a step increase by 0.7×10-5 in late 2015, (3) a linear trend of 1.4×10-5 per year from November 2015 to March 2018, and (4) a linear trend of -0.8×10-5 per year from June 2018 to March 2020. The step increase in 2015 coincided with the lava lake appearance and was thus most likely caused by a change in the magmatic system. We suggest that the cyclicity might be a manifestation of meteorological cycles. We found an anti-correlation between the BrO/SO2 molar ratios and the atmospheric water concentration (correlation coefficient of −0.47) but, in contrast to that, neither a correlation with the ozone mixing ratio (+0.21) nor systematic dependencies between the BrO/SO2 molar ratios and the atmospheric plume age for an age range of 2–20 min after the release from the volcanic edifice. The two latter observations indicate an early stop of the autocatalytic transformation of bromide Br− solved in aerosol particles to atmospheric BrO.

CONSUMPTION AND USE OF OXYGEN BY THE BODY OF PERSONS WITH CARDIOVASCULAR PATHOLOGY WITH CHANGES IN GEOMAGNETIC ACTIVITY

The aim of the study was to identify and evaluate the relationship between the indicators of solar activity, the content of magnesium in the blood and the level of oxygen utilization by tissues in men with different temperaments and anxiety, suffering from arterial hypertension. During the period of the study from 1995 to 2015, sick and healthy men were divided into equal groups with a predominance of choleric, sanguine, phlegmatic and melancholic temperament with high and low anxiety. The average annual values of the Wolf numbers, the radio emission of the Sun at a wavelength of 10,7 cm, atmospheric pressure, gamma background and air temperature were taken into account, and the content of magnesium and hemoglobin in the blood serum was determined. The oxygen concentration was determined by the calculated method. A statistically significant direct correlation has been established between the increase in solar activity (Wolf numbers, radio emission flux at a wavelength of 10.7 cm), on the one hand, and atmospheric pressure, air temperature, and the gamma background of the environment, on the other. Under the same environmental conditions, the content of magnesium in the blood and the level of oxygen utilization by the body tissues of patients with arterial hypertension decreased in the temperamental range from high- and low-anxiety sympathotonics (choleric and sanguine) to parasympathotonics (high- and low-anxiety phlegmatic and melancholic). During the study period, a statistically significant relationship was established between an increase in solar activity (Wolf numbers, radio emission flux), atmospheric pressure, air temperature, and gamma background, on the one hand, and a decrease in the content of magnesium in the blood, as well as the level of oxygen utilization by tissues in healthy high- and low-anxiety individuals and patients with arterial hypertension, regardless of temperament.